zhilizhao (12019-12-24): > I get the idea. However, if lavi is built agains version A of libavutils > and use version B at runtime, it’s not guaranteed to work with or without > access to AV_PIX_FMT_NB:
In principle, it is. > 1. For major version bump, AV_PIX_FMT_XXX may have different values > in different versions of libavutils Major bumps are precisely the time to introduce unavoidable incompatibilities. But we will not make a major bump when adding a new pixel format. > 2. For minor version bump, if there is new AV_PIX_FMT_XXX appends to > AVPixelFormat, it would be safe to use a smaller AV_PIX_FMT_NB_old. It may be safe, but it would make ff_all_formats() return not all formats, which is not acceptable. > (if we don’t know what the new format is, we don’t know how to deal with it) If we don't know what the new format is but it is relevant, then we don't use ff_all_formats(). Look at the filters that use it: mostly filters that do not depend on the frame data, only the frame properties. > libavcodec, libavfilter, and libavdevice have access to AV_PIX_FMT_NB. > > Can you help me figure out these contradictions? They are bugs, they need to be fixed. The rule is: only use AV_SOMEGHING_NB in the same library. Regards, -- Nicolas George
signature.asc
Description: PGP signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".